Recently, an information display apparatus which includes a display unit using a non-volatile display medium have been developed. An information display apparatus which includes a display unit using a electrophoretic display medium and which has a promising future due to an electric power saving ability because of an ability to maintain displayed contents without periodical (successive) driving electric power supply.
Herein, the electrophoretic display medium includes microcapsules having a diameter of about 40 micrometer containing a fluid such as oil, white color particles and black color particles, and individually moves the white color particles and black color particles by an electric field, to thereby perform apparent white color displays and black color displays. There is related art for the information display apparatus which includes the display unit using such electrophoretic display medium.
Meanwhile, in other types of the information display apparatuses such as a liquid crystal panel and a plasma display panel, a so-called “screen burn” problem is known. Screen burn refers to a phenomenon that in the case that the same image is continuously displayed for a long time, the original image is dimly displayed as a residual image on a display unit even after the original image is changed into another image, thereby causing deterioration in visibility in the display unit. Further, a variety of methods for preventing burn has been developed.